The present invention relates to a vehicle seat having a backrest middle and side parts which extend laterally from the middle part.
Modern vehicles are typically equipped with multiple airbags. In addition to airbags which are situated in the steering wheel or in the dashboard, there are seat airbags which are to protect the passenger in the event of a side impact. Seat airbags are increasingly replacing the door airbags situated behind door side panels in older vehicles.
It is expected of premium vehicles, in particular, that the vehicle seats are adaptable to the body as perfectly as possible, similarly to a tailored suit, to offer high seat comfort and good lateral hold or restraint to every passenger. Simultaneously, the vehicle seats are to meet the high safety requirements of modern vehicles.
A vehicle seat having a backrest middle part and backrest side parts, which may be adjusted in relation to the backrest middle part by an electromechanical adjustment apparatus, is known from German Patent Document DE 103 45 834.4 (not previously published), which is expressly incorporated herein its entirety, the backrest width being able to be changed by adjusting the backrest side parts. An airbag module is situated in one of the backrest side parts. A tear seam is provided in a forward external area of this backrest side part. When the airbag is triggered, the tear seam is torn open by the pressure of the airbag. The airbag may then unfold toward a forward seat area. To meet the safety standards placed on the seat airbag, the tear seam must be subjected to careful quality control in the manufacturing process, which is connected with significant costs.
According to the present invention, a vehicle seat which is adjustable in its backrest width, and which is producible at low manufacturing and quality control outlay is described.
Although the present invention is primarily described in the following in connection with a width-adjustable seat backrest, a shown in the drawings, it is expressly noted that the present invention is also suitable for a width-adjustable seat cushion.
In one exemplary embodiment, the present invention may include a vehicle seat having a backrest which has a backrest middle part and two backrest side parts, which extend forward laterally from the backrest middle part and are provided for lateral body support. The backrest side parts each have an internal section connected to the backrest middle part and an external section connected thereto, which overlaps a forward area of the particular backrest side part. The internal section may be convexly curved. However an “indented,” i.e., concavely curved internal section may also be used. The backrest side parts are situated so they are adjustable in relation to the backrest middle part in such a way that the backrest width of the vehicle seat is changeable by adjusting the backrest side parts.
An important aspect of the exemplary embodiment of the present invention is that the internal section and the external section of at least one of the two backrest side parts are produced in one piece from a foam material, a stiffening element being “foamed in” in the internal section and the external section at least in a transition area between the internal section and the external section. When reference is made in the following description to “foamed in,” the term “foamed in” is to be understood broadly in the meaning that “foamed on” and “glued on” are also included, even without the latter terms expressly being used. The stiffening element is provided for the purpose of giving the transition area between the internal section and the external section as well as the external section per se a certain rigidity. In regard to the possibility of adjusting the backrest width, the external section of the backrest side part is to have a certain flexibility. On the other hand, however, it is to be ensured that the external area of the backrest side part maintains its shape, i.e., remains taut, over the entire service life of the motor vehicle.
According to a refinement of the present exemplary embodiment, an airbag module may be situated in a rear area of the seat-exterior backrest side part. The term “seat-exterior backrest part” is to be understood as the backrest part which faces toward the vehicle exterior side or the vehicle door in the vehicle and faces away from the vehicle center. In the event of airbag triggering, the exemplary airbag exits from the backrest side part and unfolds past the external section of the seat-exterior backrest part in the direction toward a forward seat area.
According to a refinement of the present exemplary embodiment, the backrest middle part and the backrest side parts may be covered by a decorative material, e.g., a textile material or leather. The decorative material is tensioned over the internal section and the external section of the seat-exterior backrest side part and wrapped around a rear end of the external section of the seat-exterior backrest part. The wrapped-around end of the exemplary decorative material is fixed on an interior side of the external section of the seat-exterior backrest part on the external section. The wrapped-around end may be hung, clipped, glued, or attached in another way to the interior side of the external section.
The vehicle seat in this example preferably has a backrest rear wall, which has a seat-interior side face and a seat-exterior side face. The side faces extend from the rear side of the vehicle seat laterally forward to the backrest side parts. The side faces at least partially overlap the rear areas of the side parts. The seat-exterior side face preferably extends at least far enough forward that it overlaps the airbag module from the outside. The seat-exterior side face has a certain bending elasticity and only extends far enough forward that upon the airbag triggering, the airbag may exit securely from the backrest side part and may unfold forward externally past the external section of the seat-exterior backrest side part.
The airbag module may be attached to a support structure or to a frame of the seat backrest. The support structure or the frame may be a welded or bent construction. The “support structure” may also be produced from sheet metal and pipes.
In the normal state according to this embodiment, i.e., when the seat airbag has not been triggered, the forward end of the seat-exterior side face of the backrest rear wall and the rear end of the external section of the seat-exterior backrest part may essentially abut one another and/or slightly overlap one another viewed from the outside.
As described above, the backrest side parts in an exemplary embodiment may be situated so they are adjustable in relation to the backrest middle part. For design reasons, it may be ensured that the airbag module, the support structure of the seat backrest, and other seat components situated in the backrest are not visible from the outside, even when the backrest side parts are extended entirely “forward to the inside,” i.e., when the seat backrest is set to its minimal backrest width. For this purpose, a screen element may be provided. The screen element may be implemented in such a way that it has a first leg-like section and a second leg-like section. For example, it may have an L-shaped cross-section. A first leg of the screen element may be situated in such a way that it at least partially overlaps a front side of the airbag module. A second leg of the screen element may extend in an area between the interior side of the external section of the exterior backrest side part and the support structure. It is ensured by a screen element of this type that even when the backrest side parts are entirely extended, the airbag module and the support structure of the seat backrest are not visible from the outside.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.